Why do gaming companies such as Blizzard like to keep what they are working as mega secret as possible? The one two reasons I can think of are because their plans could change at any time, or they don't want the competition to know what they are up to. Which I can understand both points, but whats the worst that would happen if today Blizzard and said something like "Hey guys we are thinking about doing this or this for our next expansion and implementing these features, what do you all think?" It seems this way the community can be actually part of the development process. Now as far as their plans changing at anytime, wouldn't this problem be solved by making a disclaimer with every twitter post or what not saying that their plans could change at any time?

There's honestly a lot of reasons why we tend to keep things in extremely early development under wraps. A big one is that players tend to take "we're experimenting with something" as "it will be in the game in a couple months," no matter how many disclaimers or caveats we attach to it.

There's also plenty of situations where we just don't have enough nailed down yet to give players a clear idea of where things are heading. When we can't be clear, players tend to build up expectations about what they think the feature will be... and when it turns out to be something different, they're disappointed (even if the real feature is actually pretty cool). In most cases, we'd rather wait until we have something solid to share and avoid all of that confusion and heartache.

All that being said, we have a much more open development process today than we did when the game first launched. The PTR process starts earlier in the dev cycle, and is far more accessible. We have much more efficient means of gathering player feedback from the forums, fansites, social media, etc. Heck, we even have designers like Greg Street and Brian Holinka actively discussing changes with players on Twitter. We try to be as open as we can about what we can. :)